Fluid-pressure brake.



W. E. DEAN.

FLUID PRESSURE BRAKE.

APPLICATION FILED NOV-29.1916.

Lggfi fllfl Patented. Feb. 18, 1919.

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11M E, DEAN, 01F WILMJERDING, PENNSYLVANIA, ASSIGNOR TO THE WESTING-HOUSE E. KJE COMPANY, 01E VVILMJERDING, lPENNSYLVANIA, A CORPORATIONlE'lD'UlElD-PRJESSURE JBKE.

Specification of letters Patent.

Patented rep, in, rat,

Application filed November 29, 1916. Serial No. 134,0?5.

To all whom it may concern Be it known that 1, WILLIAM E. DEAN, acitizen of the United States, residing at Wilmerding, in the county ofAllegheny and State of Pennsylvania, have invented new and usefulImprovements in Fluid-Pressure Brakes, of which the following is aspecification.

This invention relates to fluid pressure brakes, as employed in railwayservice for stopping trains.v

In order to eliminate the possibility of the brake. cylinder pistonstriking the non-pressure head of the brake cylinder where false pistontravel due to spring of the brake riggmg and drag of the brake shoes isexcessive, it has been the practice in some cases to allow theslack'adju ster to act under the influence of false piston travel sothat a brake cylinder piston travel is obtained which is less than theamount for which the fluid pressure brake is designed, and

while the desired object of preventing the brake cylinder piston fromstriking the nonpressure head of the brake cylinder is thusaccomplished, the brake cylinder pressure obtained for a given reductionin brake pipe till tit

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pressure will be greater than desired, since the brake cylinder volumeis less than it should be.

In order to compensate for the shorter piston travel, the principalobject of my invention is to provide means for increasing the eflcctivevolume of the brake cylinder in applying the brakes.

In the accompanymgdrawing, Figure 1 is a diagrammatic view of a can airbrake equi ment, showing my improvement applie thereto, 7 oil thereservoir cut-oil" valve in position for cutting ofl the reservoir fromthe brake cylinder.

According to Fig. 1 ot the drawing, there is provided a brake cylinder 1connected by pipe 2 to a triple valve device 3 and having the usualbrake cylinder piston rod 4.

A reservoir 5 is connected by pipe 6 to the brake cylinder supply pipe 2and interposed in the pipe 6 is a cock 7 having a plug valve 8 adaptedto be operated by a handle 9.

Secured to the brakecylinder piston rod 4 is a bent rod 10 which extendsrearwardly oi" the and Fig. 2 is a sectional view brake cylinder 1,being supported by a J bracket 11 secured to the brake cylinder.

The rear end of the rod. 10 has a notch 12, within which the handle 9operates.

Inoperation, with the brakes released as shown, the valve 8 is inposition for establishing communication from reservoir 5 to pipe 2through a passage 13.

Upon applying the brakes, fluid under pressure is supplied by the usualoperation 7 of the triple valve device, 3 through pipe 2 till cockhandle 9 is turned. When the piston travel attains a predeterminedamount, say

four or five inches, the valve 8 is turned so as to out 0d the reservoir5 from the brake cylinder and upon a slightly further move ment, a port14: leading to port 13 is brought into registry with an atmosphericexhaust port 15, so that the reservoir 5 is exhausted to the atmosphere;

By thus venting fluid from the reservoir 5,

the release of the brakes is facilitated, since it is not necessary torelease the fluid in the reservoir through the exhaust port of the trile valve device. a

aving now described my 1nvention, what I claim as new and desire tosecure by lLetters Patent, is y 1. In a fluid pressure brake, thecombination with a brake cylinder, of a chamber normally connected tothe brake cylinder and means for cutting ofl communication from saidchamber to the brake cylinder upon movement of the brake cylinder pistonin applying the brakes.

2. lln a fluid pressure brake, the combination with a brake cylinder, ofa chamber normally connected to the brake cylinder and means operatedupon a predetermined brake cylinder piston travel for cutting oil"communication from said chamber to the brake cylinder.

3. in a fluid pressure brake, the combina tion with a brake cylinder, ofa reservoir,

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, a valve having apo'rt normally connecting said reservoir to the brake.cylinder and means movable with the brake cylinder pis- 4:. In a fluidpressure brake, the conrbination with a brake cylinder, of a chamber, avalve normally connecting said reservoir with the brake cylinder, andmeans movable with the brake cylinder piston in applying the brakes forcutting off communication from the reservoir to the brake cylinder andfor connecting the reservoir with the atmosphere.

In testimony whereof I hereunto set my hand.

' WILLIAM DEAN.

